Finding right starter solenoide?

[FreeBayliner4Us]

I have 1987 85hp force that will not start.

First I checked the battery: 12.9v. Thats OK. Then I checked the cables: They are good and Ohm meter reads good contenuity. I tried to bypass the starter and jump power straight to starter: Spins right up, so starter is good.
I think the solenoide is bad.
Turn the key and all you hear is one "click" come from the solenoide. I pulled the old one and went on an adventure to see if any local autoparts stores might have one.

I found one that is visually identical except it is only a three post instead of four. That and it doesn't have the rubber bushings on the mounting points.

Also the small posts on the old one have continuity between them so they would both have been grounded via the wireing. (This may have been the problem) There is no contenuity from small posts to base. The new one has contenuity from single small post to base and says "diode supressed" on the side.

So I don't know if I can adapt the three post to work or not... I think the answer is no. There is a Mercury Marine dealer about 30min away from me but I don't know if this is a common item that was used on other motors. This guy doesn't keep one Force part in stock (that would be convienent) but, he will order if paid in advance. What a swell guy! Oh, and if you order the wrong part by mistake... 20% re-stocking fee.

So I try to avoid him. That and the "marine" part is about $30 more.

Any advise would be great, I hope to be in the water tommorow night.

Thanks.

 

[eurolarva]

Re: Finding right starter solenoide?

Post your model number to be certain. Mercury part number is 89-817109A3 and cost is $40. The reason for the model number is Force put out about 10 models that year. I doubt any of them are different but better safe then sorry. Typically a three prong uses a body ground which is usually the screw holes that mount it to the motor. You can test yours by hooking 10 amp battery charger to the small lug (red+) and the black lead to the body where it attaches to the motor (black -). hook a dvm to the two big leads. When battery charger is turned on you should read near zero ohms. When charger is off you should read infinite ohms.

IF you can make it flip try cleaning all leads to starter, solenoid, battery and neutral interlock switch, barrier strip and ignition switch. What could be happening is that solenoid only had like .6 ohms. All the wire and contacts in your circuit create a voltage divider and by the time the voltage is getting to the solenoid your voltage drop may be so severe (less then 9 volts) that the solenoid is not firing. Then again you could have a shot solenoid

 

[FreeBayliner4Us]

Re: Finding right starter solenoide?

I matched mine to a Sierra part# 18-5835 found on this site's Marine Store.

This is what came off of the boat. I will head to the dealer in the morning and hopefully he has the Merc equivelant in stock.

Thanks for the quick responce!

 

[seagull369]

Re: Finding right starter solenoide?

Usually when a solenoid (or relay) clicks, it means it's working fine. If youre hearing it click on and off when you turn the key to start and back respectively, it's probably ok.

Solenoids in general, are basically switches that allow a smaller current to control a larger one. Turning the ignition to start sends a small current to the solenoid, and if it's properly grounded, the sol- will click and allow a larger current to flow through it and on to the starter. In the diagram I inserted, when the key is turned to the start position, it sends +12V to the solenoid, again it clicks, and allows current from the battery to flow through it and on to the starter. Most starter solenoids have this kind of hookup.

eurolarva is most likely correct that the 4th terminal on your oem one is for ground. If youre handy and the sol- does turn out to be your problem, you can get away with using the auto parts store one if you can fashioning up a ground wire the thing somehow. Don;t worry about the lack of bushings, btw.

One more thought, there isnt a circuit breaker or anything between the -noid and starter is there?

 

[FreeBayliner4Us]

Re: Finding right starter solenoide?

Well a great and productive day... (sarcasm)

I made the trip to the Merc dealer this morning. He didn't have the soliniod. Sent me to another dealer. He didn't have it and reffered me to another guy... He didn't have it.

Well I figure I will just have to order it and went back to my dealer. I left there with a laugh when he informed me he wanted $59 for it! So I drove home and ordered it online for $48 including shipping to my door.

Spent $15 in gas and 2.5hrs of running around only to come right back home and do what I figured I was going to do anyway. Go figure!